Many printers employ continuous webs of paper known as "Z-fold" paper stock for large print jobs. A box of Z-fold paper often contains 2000-3000 sheets, depending upon the paper weight. Prior art stackers have, in the main, been only able to stack 400-500 sheets of such Z-fold stock before allowing the remainder to spill onto the floor.
Prior art stackers also have allowed the paper to pass too close to the back of the printer where a static charge build up could occur. Such static charge caused the paper to adhere to the back of the machine and impeded its proper stacking.
In U.S. Pat. No. 4,559,031 to Gysling et al., assigned to the same assignee as this application, a passive paper stacker is shown wherein paper output from a printer is guided by an exit ramp toward a base, where the paper is automatically stacked. The base includes a starter ramp for automatically positioning a first page of the paper to permit orderly stacking of later pages. A set of paper-fold "dive-arrestors" are employed to catch diving folds and redirect then towards their proper position on the stack of paper. The operation of the dive arrestor, however, may force the paper into contact with the surface of the printer, where a static charge can be acquired that hinders the paper's stacking. Further, once the paper stack reaches the bottommost edge of the dive arrestors, the paper no longer is able to stack in an orderly manner.
Accordingly, it is an object of this invention to provide a passive paper stacker particularly adapted to handling large quantities of Z-fold paper stock.
It is another object of this invention to provide a passive paper stacker that has the capability to properly stack up to 3000 sheets of Z-fold paper.
It is yet another object of this invention to provide a passive paper stacker for a printer which is constructed to avoid the occurrence of static charge build up as paper is being stacked.